Dear Developers,
If I want to calculate the electronic coupling between the two fragments but I also have a linker chain present between these two fragments, how can I use FODFT in this case? Can I mention three fragments and only calculate the coupling between the two of those fragments? or is there a way to mention the supermolecule separately and the fragments separately like in CDFT-CI?
A couple of thoughts:
(1) If you think the linker is electronically unimportant, why not delete it, cap the chromophores, and use any of several fragment-based methods to compute the coupling?
(2) Or, you could compute adiabatic excitation energies (e.g., using TDDFT) then estimate the coupling from the splitting. Depending on how far apart the chromophores are, this may be somewhat less rigorous because it doesn’t account for overlap of the fragment wave functions.
Linker is needed since they are important while looking at the enzymatic ET pathways.
But you only want the coupling between the chromophores, so apparently not.
If you want to include the linker, then you’ve got a challenging problem for which you should consult the literature.